MPEG-7 is a multimedia content description standard. It was standardized in ISO/IEC 15938 (Multimedia content description interface). This description will be associated with the content itself, to allow fast and efficient searching for material that is of interest to the user. MPEG-7 is formally called Multimedia Content Description Interface. Thus, it is not a standard which deals with the actual encoding of moving pictures and audio, like MPEG-1, MPEG-2 and MPEG-4. It uses XML to store metadata, and can be attached to timecode in order to tag particular events, or synchronise lyrics to a song, for example. It was designed to standardize: \n* a set of Description Schemes ("DS") and Descriptors ("D") \n* a language to specify these schemes, called the Description Definition Language ("DDL") \n* a scheme for coding the description The combination of MPEG-4 and MPEG-7 has been sometimes referred to as MPEG-47.